For the second straight year, the state has recorded a significant increase in the number of fatal heroin overdoses.

According to figures provided by the state’s Office of the Chief Medical Examiner, 325 people died of overdoses involving heroin in 2014, which is up from 257 in 2013 and 174 in 2012.

Public officials in all levels of state government have joined federal officials in publicly decrying heroin use as an issue in need of attention. Gov. Dannel P. Malloy met with the governors of four New England states in June to discuss how they could help decrease the number of fatal overdoses in the region.

The number of fatal overdoses involving heroin is less than the projected total for 2014, as an official from the examiner’s office estimated last summer there could be 376 accidental opioid deaths by the end of the year. The estimate was based on data from the first quarter of the year.

Accidental deaths where heroin, morphine and or codeine were detected totalled 347 in 2014, up from 284 in 2013 and 195 in 2012. The figures showed 115 people died of heroin use alone, which is up from 109 in 2013 and 86 in 2012. Deaths involving fentanyl, a synthetic opioid more than 100 times more potent than morphine, rose sharply, as 75 people died of overdoses involving fentanyl in 2014, up from 37 in 2013 and 14 in 2012. At least 37 people died from a mixture of heroin and fentanyl use, up from nine in 2013 and one in 2012. State law enforcement agencies have warned that fentanyl is often sold as heroin.

Dr. James Gill, the state’s chief medical examiner, said in an email that on average, it takes the office 11 days to determine the drugs in a person’s system after their death. Additional drugs can stretch the process out to as much as 30 days, he said.

“In rare instances, we may only be able to detect the class of the drug (opioid or opiate) or the metabolites and we cannot identify the specific drug,” Gill said.

Gill said “opioid” is a general term for substances that affect the opioid receptor in the brain; “opiates” are naturally occurring, such as morphine and codeine, while “opioids” refers to all other drugs that affect the opioid receptor. This includes synthetic drugs like fentanyl and heroin, which Gill said is a semisynthetic opioid. Gill added that heroin eventually metabolizes, or breaks down, to morphine, which can sometimes lead to problems when trying to identify the kind of drug in a body.

“Heroin has a short half life but we often can detect it or its unique metabolite (6-mam) in the blood or other fluids,” Gill said.

Intoxication deaths are a type of chemical injury, which is why they are referred to as “accidental,” Gill said, as such injuries cannot be called natural.

According to the figures, 558 people died of accidental intoxication deaths that in addition to heroin include drugs like cocaine, codeine, fentanyl, morphine and methadone.

Victoria E. Richards, as associate professor of medical sciences at Quinnipiac University, said last month that among the positive efforts developed to help combat opioid use in Connecticut was Malloy’s signing of a bill allowing anyone to administer the opioid overdose-reversal drug naloxone, also known as Narcan.

“I think that being approved and that not being hampered or (experiencing) pushback ... I think that’s a positive step,” Richards said, adding that letting more people administer the drug could help prevent some of the deaths.

However, Richards said that the increase in fatal overdoses shows there is not enough being done.